Sprayable perfluoropolyether / poly(ethylene glycol) segmented polyurethane coatings with micron-scale phase separated 3D structure

Abstract

A series of perfluoropolyether (PFPE)/poly (ethylene glycol) (PEG) segmented polyurethanes were found to produce micron-scale phase separation across a range of fluoro content as high as 75% PFPE/25% PEG mole composition. In spite of immiscibility of the PFPE precursor, samples were capable of dispersion and spray application to surfaces before curing where they expressed micron-length scale phase separation with continuous (PEG) and discrete (PFPE) regions. This two-phase morphology was present at the air interface and continued through the film thickness creating a continuous hydrophilic and discrete hydrophobic phase structure capable of ionic conductance as a free standing film. These materials also display tough elastomeric character (ε > 150%, σ > 16 MPa) and are wear resistant under abrasion. The chemical inhomogeneity and corresponding physical properties of the system combined with synthetic tunability and toughness creates potential application areas in energy, environmental technology, self-healing applications and biotechnology.